The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A210208 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A210208

Triangle read by rows in which row n lists the divisors of n that are prime powers, A000961.
(history; published version)

#16 by Michel Marcus at Sun Feb 08 15:05:56 EST 2015

STATUS

reviewed

approved

#15 by Joerg Arndt at Sun Feb 08 14:21:31 EST 2015

STATUS

proposed

reviewed

#14 by Geoffrey Critzer at Sun Feb 08 06:18:21 EST 2015

STATUS

editing

proposed

#13 by Geoffrey Critzer at Sun Feb 08 06:17:57 EST 2015

EXAMPLE

1;

1, 2;

1, 3;

1, 2, 4;

1, 5;

1, 2, 3;

1, 7;

1, 2, 4, 8;

1, 3, 9;

1, 2, 5;

1, 11;

1 1, 2 1, 31, 2, 41, 51, 2, 31, 71, 2, 4,81, 3, 91, 2, 54; - Geoffrey Critzer, Feb 08 2015

#12 by Geoffrey Critzer at Sun Feb 08 06:14:01 EST 2015

EXAMPLE

1 1, 2 1, 31, 2, 41, 51, 2, 31, 71, 2, 4,81, 3, 91, 2, 5- Geoffrey Critzer, Feb 08 2015

MATHEMATICA

Table[Prepend[Select[Divisors[n], PrimeNu[#] == 1 &], 1], {n, 1, 10}]//Grid (* Geoffrey Critzer, Feb 08 2015 *)

STATUS

approved

editing

#11 by Charles R Greathouse IV at Sat Jul 13 12:04:24 EDT 2013

LINKS

_Reinhard Zumkeller_, , <a href="/A210208/b210208.txt">Rows n=1..5000 of triangle, flattened</a>

Discussion

Sat Jul 13

12:04

OEIS Server: https://oeis.org/edit/global/1934

#10 by N. J. A. Sloane at Fri Feb 22 21:39:15 EST 2013

LINKS

_Reinhard Zumkeller, _, <a href="/A210208/b210208.txt">Rows n=1..5000 of triangle, flattened</a>

Discussion

Fri Feb 22

21:39

OEIS Server: https://oeis.org/edit/global/1866

#9 by Russ Cox at Fri Mar 30 18:51:12 EDT 2012

AUTHOR

_Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), _, Mar 18 2012

Discussion

Fri Mar 30

18:51

OEIS Server: https://oeis.org/edit/global/246

#8 by Bruno Berselli at Fri Mar 23 07:18:38 EDT 2012

STATUS

proposed

approved

#7 by Reinhard Zumkeller at Thu Mar 22 21:06:33 EDT 2012

STATUS

editing

proposed